1. An election by or on behalf of a surviving spouse to take the share provided in section 633.211, 633.212, 633.236, 633.238, 633.240, or 633.244 shall be binding and shall not be subject to change except for such causes as would justify an equitable decree for the rescission of a deed.
 2. An affirmative election to take under the will, receive the intestate share, or take under the revocable trust shall be irrevocable when filed as provided in section 633.237.